<div class="container">
  <button>
  Button
  </button>
</div>
<style>
/* From Uiverse.io by alessandrodesign - Tags: button */
button {
  display: -webkit-box;
  display: -ms-flexbox;
  display: flex;
  -webkit-box-pack: center;
  -ms-flex-pack: center;
  justify-content: center;
  -webkit-box-align: center;
  -ms-flex-align: center;
  align-items: center;
  background: rgba(255, 255, 255, 0.2);
  border: 2px solid #26c4c3;
  border-right-color: transparent;
  -webkit-box-shadow: 0 4px 20px rgba(0, 0, 0, 1), 0 0 10px rgb(194,255,255);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 1), 0 0 10px rgb(194,255,255);
  -webkit-clip-path: polygon(0% 0%, 0% 100%, 100% 100%, 100% 20%, 100% 20%, 85% 100%, 80% 100%, 95% 20%, 50% 20%, 30% 0);
  clip-path: polygon(0% 0%, 0% 100%, 100% 100%, 100% 20%, 100% 20%, 85% 100%, 80% 100%, 95% 20%, 50% 20%, 30% 0);
  backdrop-filter: blur(2px);
  -webkit-backdrop-filter: blur(2px);
  width: 150px;
  height: 55px;
  font-size: 1.5rem;
  color: white;
  text-shadow: 0 1px 1px black;
  position: relative;
  -webkit-transition: all .5s ease-in-out;
  transition: all .5s ease-in-out;
}

button:hover {
  -webkit-clip-path: polygon(0% 0%, 0% 100%, 100% 100%, 100% 20%, 100% 20%, 100% 100%, 100% 100%, 100% 20%, 50% 20%, 30% 0);
  clip-path: polygon(0% 0%, 0% 100%, 100% 100%, 100% 20%, 100% 20%, 100% 100%, 100% 100%, 100% 20%, 50% 20%, 30% 0);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
}

button::after {
  content: '';
  position: absolute;
  display: block;
  top: 0;
  left: 0;
  width: 50%;
  height: 5px;
  background-color: rgb(194,255,255);
  -webkit-box-shadow: 0 0 5px rgb(194,255,255);
  box-shadow: 0 0 5px rgb(194,255,255);
  -webkit-transform: translateY(-50%);
  -ms-transform: translateY(-50%);
  transform: translateY(-50%);
  z-index: 2;
  -webkit-animation: btn 1s infinite ease-in-out;
  animation: btn 1s infinite ease-in-out;
}

button::before {
  content: '';
  position: absolute;
  display: block;
  bottom: 0;
  right: 0;
  width: 100%;
  height: 5px;
  background-color: rgb(194,255,255);
  -webkit-box-shadow: 0 0 5px rgb(194,255,255);
  box-shadow: 0 0 5px rgb(194,255,255);
  -webkit-transform: translateY(50%);
  -ms-transform: translateY(50%);
  transform: translateY(50%);
  z-index: 3;
  animation: btn_51 1s infinite ease-in-out reverse;
}

@keyframes btn_51 {
  0%,100% {
    width: 100%;
  }

  25%,75% {
    width: 0;
  }

  50% {
    width: 50%;
  }
}
</style>
